Fig. 4From: The increased in vivo firing of pyramidal cells but not interneurons in the anterior cingulate cortex after neuropathic painOptical HFS induction of ACC afferent fibers increases the activities of ACC pyramidal cells and induces pain hypersensitivity. A Experimental timeline. B Schematic showing that, with the injection of rAAV-CaMKIIα-ChR2 (E123T/T159C)-mCherry into the ipsilateral mediodorsal thalamic nucleus (MD), an optic fiber was implanted into the ACC through the multi-channel recording system and the in vivo spikes of ACC neurons are recorded. The coronal sections of virus injection site in the MD and mCherry+ projecting fibers in the ACC are shown on the right panel. Scale bars = 500 μm. C PWMT before (0 h) and after oHFS induction in sham and SNI mice. *p < 0.05; **p < 0.01; ***p < 0.001, compared with baseline (0 h) (n = 8 mice in each group, One Way ANOVA with Dunnett post hoc analysis). D Histograms of the inter-spike intervals (ISI) from the spikes of a pyramidal cell and an interneuron in baseline and post-HFS recording period. Insets at the top right corner show the waveforms of the detected single unit. E The averaged firing rate of pyramidal cells (PYR) in sham and SNI group before and after oHFS induction. ***p < 0.001, n = 3 mice in sham and SNI group, paired t-test. F Proportion of pyramidal cells with changed firing rate in sham and SNI groups. Pie charts summarize the changes in firing rate of pyramidal cells in sham (n = 183 neurons) or SNI (n = 174 neurons) groups. Pre vs. post oHFS induction, Wilcoxon rank-sum test. G The averaged firing rate of interneurons (INT) in sham and SNI group before and after oHFS induction. n.s. not significant, n = 3 mice in sham and SNI group, paired t-test. H Proportion of interneurons with changed firing rate in sham and SNI groups. Pie charts summarize the changes in firing rate of interneurons in sham (n = 37 neurons) or SNI (n = 43 neurons) groups. Pre vs. post oHFS induction, Wilcoxon rank-sum testBack to article page